Key Lime Fudge

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This Key Lime Fudge recipe has turned out to be a very popular fudge recipe.  It’s sweet and delicious, and it has that tangy taste of lime that we love so much in key lime pie! Watch the short how-to video showing you how to make this fudge, and then you can scroll to the bottom of this post and print out the recipe so you can make it at home.

Stack of Key Lime Fudge

Key Lime Fudge

It’s not a typical fudge flavor at all.  In fact, it’s not even chocolate!  There’s white chocolate in the recipe, but we all know that’s not really chocolate.  The white chocolate acts as a vessel for containing an amazing sweet lime flavor.  If you’re a lime lover, then this fudge recipe is for you.

Key Lime Fudge is a nice fudge to make during the holiday season to place on holiday treat platters or for gifting to friends and neighbors.  I think people like to see and sample something that is a little different.  This is definitely different than your typical fudge recipe.

Key Lime Fudge

What are Key Limes?

Key limes get their name from the Florida Keys, where Key Lime Pies are abundant! They have a stronger scent and a thinner rind than the typical lime.  The flavor is more tart and bitter.

Have you ever picked up a bag of key limes?  They’re awfully cute.  They’re tiny little things.  You’ve gotta squeeze the heck out of them to get every bit of their juice, but it’s all worth it.

These limes present themselves nicely in sweet treats (like key lime pie!) since the sugar balances out that tart flavor and highlights the unique flavor of the key lime.  I love them!  And if you love them too, then you must try my Key Lime Pie Ice Cream!

Key Lime Fudge

How do you make Key Lime Fudge?

Evaporated milk, sugar and salt are heated together in a saucepan and boiled for 8 minutes.  Once that mixture has boiled for several minutes, it’ll be piping hot.  At that point, you’ll pull the pan off the stove and stir in marshmallows, white chocolate, lime zest and lime juice.  All should melt nicely, and then you’ll scrape the fudge mixture into a pan to cool.  Once cooled, it’s ready to be cut into squares and eaten!

stack of Key Lime Fudge

Can you use regular limes to make Key Lime Fudge?

You can most certainly use regular limes for this fudge.  They might give the fudge a slightly sweeter flavor, but all will still be good.  Don’t skimp on the lime zest in this recipe since it gives the fudge a fabulous green tint, and it adds a good amount of lime flavor to the recipe too.  Oh, and if you want to make the whole process of making this Key Lime Fudge a zillion times easier, then just buy Nellie & Joe’s Key Lime Juice in your market’s juice section.  It’ll work just fine for this recipe!

So if you’re wishing for a little “spring” in your life and it hasn’t quite arrived yet, treat yourself to some Key Lime Fudge instead.  Or surprise gift your friends for the holidays with a little Key Lime Fudge!

If you’re as obsessed with lime as I am, you might also enjoy my Iced Lemon Lime Cookies or this Lime- Coconut Buttermilk Pie. Lime Sugar Cookies, Chicken with Lime Butter and Super Easy Lime Bars are delicious lime recipes too!

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4.8 from 5 votes

Key Lime Fudge

This Key Lime Fudge recipe is the perfect blend of sweet and sour!
Prep Time 15 minutes
Cook Time 8 minutes
Total Time 23 minutes
Servings 36 pieces
Calories 100kcal
Course Dessert
Cuisine American
Keyword key lime fudge


  • One 5-ounce can 2% evaporated milk
  • 1 2/3 cups granulated white sugar
  • 1/2 teaspoon salt
  • 12 large marshmallows
  • 2 cups white chocolate chips
  • 1/4 cup grated lime zest (about 5 limes)
  • 2 tablespoons key lime juice (5 to 7 limes, juiced)


  • Line an 8" x 8" square pan with aluminum foil; grease the foil with butter. It's not a good recipe for a 9-inch square pan as the fudge will be too thin.
  • Combine the milk, sugar and salt in a large heavy saucepan over medium heat. Stir and bring to a boil; boil 8 minutes, stirring constantly at a boil (if you have a candy thermometer, you can bring it to the soft-ball-stage, but I didn't use one). Remove the pan from heat. Add the marshmallows, chocolate, zest and juice, and stir until the marshmallows and chocolate are melted and the mixture is smooth. Scrape the fudge into the prepared pan. Tip the pan to make sure the fudge covers the bottom evenly. Cool completely, then cut into 1-inch squares.



*This recipe can be made with regular limes too.


Serving: 1piece | Calories: 100kcal | Carbohydrates: 17g | Fat: 3g | Saturated Fat: 1g | Cholesterol: 2mg | Sodium: 47mg | Potassium: 28mg | Sugar: 16g | Vitamin A: 5IU | Vitamin C: 0.2mg | Calcium: 21mg | Iron: 0mg
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  • Kim wrote:

    I made this last week for a party sadly it was woofed down by everybody before the party now going to have to make it again absolutely fantastic recipe will be doing this again and again thank you so much for posting it

    • Lori Lange wrote:

      Happy to hear!

  • Kim wrote:

    Hi good morning I am going to make this recipe as it looks super , but not sure about the large marshmallow we seem to have mini or giant here in UK so if possible can you give a an idea of weight of the marshmallows then I can use whatever I can get. Many thanks Kim

    • Lori Lange wrote:

      According to Google, one regular (large) marshmallow weighs 7 grams.

  • Sue Andryuk wrote:

    How much of Nellie and Joe’s key lime juice should u use

    • Lori Lange wrote:

      Did you see the recipe? It’s two tablespoons.

  • Nora Dolan wrote:

    Hi, Can I sub the marshmallows with anything else? I really hate them! Thanks, Nora

    • Lori Lange wrote:

      I’m afraid not– this is a marshmallow-based fudge recipe!

  • Dan Jenkins wrote:

    Overall, a good recipe. Firstly, I live overseas in SEAsia, so marshmallows are problematic. Homemade marshmallow cream works just as well. Secondly, way too much sugar. You’ve got sugar in the white chocolate, sugar in the marshmallow cream, and yes.. more sugar. I found 1 cup to be more than enough. Thirdly, too much zest tends to leave a bitter aftertaste, at least with the amount indicated. Fourth, I added 4 tablespoons of lime juice just because i like the intense flavor. You could do a 50-50 with lemon/lime also.

  • Wendy Arrington wrote:

    Hi, I made the Key lime fudge, and I have to admit I’ve never made any kind of fudge before, but I have a tree brimming with Key limes, so I tried it… WOW! I loved it! I took the batch to a church social, and everybody there loved it, too! It was way simpler to make than I’d imagined. SO, my question: I was so successful with your citrus fudge recipe, would it work if I followed the recipe exactly but substituted real oranges for the limes? And, could I also try adding semi-sweet chocolate chips instead of white ‘chocolate’ chips?? I’ve looked online for orange fudge recipes and chocolate orange fudge recipes, but nothing compares to the ingredients of your Key Lime Fudge. I also don’t own a microwave, so your stove top technique is perfect for me. Thanks in advance!

    • Lori Lange wrote:

      I’m so late in responding to this comment (sorry!), and I’m wondering if you tried this??

  • Jeanne Collins wrote:

    Can I use fat free evaporated milk instead of the 2%?? Apparently, here in the South we only have the regular or fat free. Cant seem to find the 2%. Thanks for any advice!!

    • Lori Lange wrote:

      I am not sure about fat-free because I haven’t tried it!

  • Natalie wrote:

    These fudge bars look so delicious and so easy to make! I love the idea of making key lime fudge – sounds yummy!

  • Cat Lennon wrote:

    Ripe key limes are yellow (and because the rind is so thin, almost impossible to zest)  so I assume the zest is from regular limes? 

    Also the riper they are the easier to juice so if try to buy yellow ones.  Unfortunately they package them in those green mesh bags which make it hard to tell. 

  • shifu wrote:

    Thanks Lori. I’ll try it this weekend. Perfect spring snack 🙂

  • Michelle wrote:

    This looks amazing!

    Question: does the recipe actually call for 1/4 CUP of zest, or is this a typo? Especially wondering since five tiny key limes would hardly produce that much. 

    • Lori Lange wrote:

      yes! Zest away!